Abstract Background This study aims to investigate the applicability of the Youth Physical Activity Promotion (YPAP) model among Chinese middle school students, focusing on the roles of reinforcing, enabling, and predisposing factors in adolescents’ physical activity participation. Specifically, the research analysed the direct and indirect effects of parental support, physical education, as well as adolescents’ perceived “Am I able” and “Is it worth it” on their participation in physical activities. Methods A quantitative research design was adopted, with data collection relying on cross-sectional questionnaires. The participants were middle school students from grades 7, 8, and 9 in Zhaoqing City, China. A total of 463 samples (223 boys; 240 girls; M age = 13.08 years; SD = 0.820) were used for data analysis. Structural equation modeling (SEM) analyzed the interactive relationships among YPAP model variables. Results The YPAP model showed good fit indices, explaining 61.7% of the variance in adolescents’ physical activity participation. The findings revealed that reinforcing and enabling factors had significant direct effects on adolescents’ physical activity participation. Moreover, both the concepts of “Am I able” and “Is it worth it” mediated the relationship between parental support and physical activity participation. Physical education also indirectly influenced adolescents’ physical activity participation through the concept of “Am I able”. Notably, the concepts of “Am I able” and “Is it worth it” serially mediated the relationships between both reinforcing factors and physical activity participation, as well as enabling factors and physical activity participation. Conclusions The study validates the YPAP model in the context of Chinese middle school students, highlighting the importance of parental support and physical education in promoting physical activity. Parents and schools should focus on enhancing adolescents’ self-concept of ability and value perception to foster long-term engagement in physical activities. These findings provide valuable insights for designing targeted interventions to address the global issue of insufficient physical activity among adolescents.